Our 5 Best Container Gardening Tips

‘Container’ gardening, as it is more often referred to, is growing in popularity faster than people can move into high-rise condos. And it isn’t just balcony gardeners who are planting up virtually everything that will hold soil. Patios, decks, front doors and walkways are enhanced with containers full of colour and food plants everywhere.

So, what are the secrets to growing successfully in containers? Here are our top tips:

1. Choose the right container. Whatever you choose to plant in, make sure that it has adequate drainage for water to move through the soil and out the hole in the bottom efficiently. If plants sit in water they rot, unless they are water plants which really belong in a pond.

Where containers are concerned, the greater the soil mass, the better the performance of the plants. This is why we do not recommend the small 10 inch hanging baskets that are so tempting. Large hangers, that are at least 14 inches in diameter, are so much better. Potting up geraniums in your uncle’s old boots might be cute but even his big feet are not big enough to create a cavity for soil to sustain plant life. A half-barrel sized container is much better. And no one wears half-barrels on their feet.

2. Choose the plants for the location of the container. If your container is in full, blazing sun be sure to plant sun loving plants in it. This is more important in containers than it is in the garden as the strength of the sun intensifies ‘off the ground’. Look for dwarf zinnias, asparagus fern (a member of the lily family), petunias, million bells, scabiosa, lobelia and the list goes on.

On the other hand, perennial hosta makes a great containerized plant in the shade or partial shade. And with a little care it will come back each year. As will many other perennials.

3. Choose quality soil. Remove last year’s soil that was in your containers, placing it on the garden where earth worms will pull it down and incorporate it into the soil. If you live in a condo, ask management if you can place it in the condo garden. Just don’t leave it in the container two years in a row. It is tired; the nutrients in it are used up. But it is fine to spread over an established garden.

When looking for container mix, buy quality: a good rule with soil is, we believe, you really get what you pay for. Choose a brand that you trust (Mark’s Choice Container mix from Home Hardware is very good!) Quality soil drains well, is full of nutrients that help to boost plant life through the growing season and some mixes feature water-retaining abilities that reduce the frequency of water applications. We add worm castings at the rate of one-part castings to 10 parts soil, or quality compost at one-part compost to five-parts soil, for the very best performance.

4. Water with the rain. Use a rain barrel to hold rainwater and apply this to your container plants throughout the season. This is how we water all my containers and our experience tells us that it makes a world of difference. Rainwater is soft, is charged with oxygen and it is almost always warm, unlike tap water. If only plants could talk, they would tell us that this is their preference. “I hate cold showers!” you would hear them roar.

Allow container soil to dry to the touch between watering applications. When water evaporates or transpires through a plant, the space that it takes in the soil is replaced with oxygen-rich air. All plants love this. Some plants, like geraniums, prefer to get quite dry, but never bone dry. In time, you will learn what works best for you in your living situation.

5. Fertilize. There are many options where ‘plant food’ is concerned. The bottom line is that containerized plants demand more nutrients than ‘garden bound’ plants as their roots are limited by the walls of the container and the volume of soil at their roots. From several meters away, we can usually tell if a plant is hungry, especially late in the season when nutrients in the container mix have been used up. Yellowing leaves, poorly performing flowers or fruit and a look of general malaise takes over a plant that is hungry. There are many fertilizers on the market, some synthetic and others natural, including a new organic that lasts all season long called ProMix Multi-Purpose Garden Fertilizer.

What is more important than all of this, if you want the very best show of colour or crop of tomatoes from your containers? Your choice of plants, of course.